Incorporation of Palladium Catalyst Inside Cross-Linked Chitosan Hybrid Nanofibers for the Sonogashira Reaction

Abstract Nanofibers are attractive supporting matrices for catalytically active metallic catalysts. Herein, palladium species were successfully incorporated into the modified chitosan/poly(ethylene oxide)/maleic acid nanofibers by electrospinning. Then, the hybrid nanofibers were thermally cross-linked at elevated temperature to improve stable behavior in solution. X-ray diffraction and transmission electron microscopy characterizations show that the palladium nanoparticles are dispersed uniformly inside the hybrid nanofibers. This novel hybrid nanofiber mat displayed high catalytic activity for the Sonogashira coupling reaction of phenyl acetylene with aromatic iodides under copper free condition with moderate to excellent yields. Moreover, this nanofiber mat could be reused 10 times with little activity loss. Thus, we have proposed a facile way to prepare highly active and stable heterogeneous palladium catalyst.